Description: The plant is considered to be a miniature cactus. It only grows to be 4 cm high and has a 5-6cm diameterFlowers of this species have a silky appearance and range from white, greenish/tan to pink.Remaks:Gymnocalycium friedrichii and Gymnocalycium stenopleurum are sometimes combined with Gymnocalycium mihanovichii, and sometimes kept as separate species. G. friedrichii and G. stenopleurum are quite districted of from G. mihanovichii, but many intermediate forms are also known and nowadays it is suggested that all should be combined into only one variable species.

Subspecies, varieties, forms and cultivars of plants belonging to the Gymnocalycium mihanovichii/stenopleurum group

The name Gymnocalycium mihanovichii v. friedrichii was introduced by Werdermann in 1936. Pazout suggested the name G. friedrichii nom. inval. in 1964 but it has not been officially approved. In 1979 Ritter made a description of Gymnocalycium stenopleurum that sometimes can be found under the incorrect name G. mihanovichii v. stenopleurum n. n. (don't confuse it with v. stenogonum). Thus we have 3 taxa: "mihanovichii", "friedrichii" and "stenopleurum". Not taking into account their taxonomic definition they are basic points of the complex with many transitional forms between. These three taxa spread from south to north (North-Western Paraguay): The typical "mihanovichii" inhabits the very south of the area – south and south-east of province Boqueron; "stenopleurum" inhabits a limited area on the very north – in Cerro Leon region and has characteristic recognizable habitus; for "friedrichii" all the area between two mentioned points is indicated.

Gymnocalycium friedrichii(Werderm.) Pazout: Distingushed from Gymnocalycium miahanovichii for the prevalently purplish pink, wide open flowers and well-pronounced polymorphism of spines. Besides it has tall slender ribs and roller-shaped prominent thickening around areoles.

Gymnocalycium mihanovichii(Frič ex Gürke) Britton & Rose: It has wider, lower ribs, in juvenile plants divided into separate chins, in maturity every rib have flat surface and a pleat above each areole. But the essential thing is its pale or brownish-yellow, not fully opening flower.

Notes: Furthermore a number of readily distinguished multicoloured and variegated cultivars (cv. NISHIKI) only partially de-coloured) are now available. Some of this plants can be grown on their own roots and are very beautiful.

Cultivation and Propagation: Gymnocalycium friedrichii is a summer grower species that is easy to cultivate. Growth rate: It is a relatively rapidly growing and easily flowering species. Soils: It likes very porous standard cactus mix soil. Prefer a low pH compost, avoid substrata rich in limestone; otherwise growth will stop altogether. Repotting: This plant needs plenty of space for its roots, repotting should be done every other year or when the it has outgrown its pot. Use pot with good drainage.Watering: Needs moderate to copious waterings in summer, but do not overwater (Rot prone), keep dry in winter at a minimum temperature of 0°C. Fertilization: Feed with a high potassium fertilizer in summer. Hardiness: Quite frost resistant if kept dry -5° C (Temperature Zone USDA 9-10), but for safe cultivation it is best to avoid freezing temperatures. Exposition: The plant tolerates extremely bright situations but enjoys filtered sunlight or afternoon shade, inside it needs bright light, and some direct sun. Tends to bronze in strong light, which encourages flowering and heavy spine production, but is likely to suffer from sun scorch or stunted growth if over exposed to direct sunlight during the hottest part of the day in summer. Uses: It is an excellent plant for container growing. It always looks good and stays small. It look fine in a cold greenhouse and frame or outdoor in a rockery.Pests & diseases: It may be attractive to a variety of insects, but plants in good condition should be nearly pest-free, particularly if they are grown in a mineral potting-mix, with good exposure and ventilation. Nonetheless, there are several pests to watch for: - Red spiders: Red spiders may be effectively rubbed up by watering the plants from above.- Mealy bugs: Mealy bugs occasionally develop aerial into the new growth among the wool with disfiguring results, but the worst types develop underground on the roots and are invisible except by their effects. - Scales: Scales are rarely a problem. - Rot: This species is particularly easy and accommodating, seldom suffer of cryptogamic diseases. Rot it is only a minor problem with gymnocalyciums if the plants are watered and “aired” correctly. If they are not, fungicides won't help all that much.Propagation: Seeds (seldom produces offsets). Seeds germinate in 7-14 days at 21-27° C in spring, remove gradually the glass cover as soon the plants will be well rooted (ca 1-2 weeks) and keep ventilated, no full sun for young plants! Colour mutants and variegates cultivars are propagated by graft.